Manufacturing methods of semiconductor devices and a solid state image pickup device

ABSTRACT

A manufacturing method of manufacturing a semiconductor device having a plurality of wiring layers. The method includes the steps of forming a wiring by a first wiring layer as a pattern by dividing a desired pattern into a plurality of patterns, connecting the divided patterns, and exposing them, wherein a position of the connection is formed in parallel with the wiring which is formed by the first wiring layer, and forming a wiring by a second wiring layer having an area which intersects the connecting position by a batch processing of exposure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to methods of manufacturing a semiconductor deviceand a solid state image pickup device and, more particularly, to amethod of manufacturing a semiconductor device and a solid state imagepickup device using connecting exposure in which a desired pattern isdivided into a plurality of patterns, the divided patterns areconnected, and exposure is executed.

2. Related Background Art

In the case of forming a semiconductor device of a large chip size ontoa semiconductor substrate, for example, a method of manufacturing thesemiconductor device disclosed in U.S. Pat. No. 5,561,317, or the like,has been known.

FIGS. 13A to 13C are diagrams for explaining the manufacturing method ofthe semiconductor device disclosed in the U.S. patent referenced above.

FIG. 13A is a diagram showing a schematic pattern of a first layer onthe semiconductor substrate. FIG. 13B is a diagram showing a schematicpattern of a first reticle which is used to form the first layer in FIG.13A. FIG. 13C is a diagram showing a schematic pattern of a secondreticle for forming a second layer.

Three patterns A, B, and C are divisionally provided in a first reticle105. An IC pattern is formed in each pattern. The patterns A, B, and Care vertically arranged and connected and one chip is constructed by theconnected patterns A, B, and C.

The first reticle 105 is set into a reduction projection type exposingapparatus. A layout of the first layer on a semiconductor substrate 101(hereinafter, referred to as a wafer 101) is programmed in a manner suchthat the connected patterns shown in FIG. 13A are printed onto the wafer101 by a system associated with the exposing apparatus. An alignmentmark 103 shown in FIG. 13B is an alignment mark of a die-by-die system.As shown in FIG. 13A, after the patterns are exposed, the alignmentmarks 103 are formed on both sides of each of the connected patterns A,B, and C on the semiconductor substrate and become alignment marks(parent marks) 102 for the second layer.

When the first layer is printed, in the first reticle 105, by changing aposition of a masking blade of the reduction projection type exposingapparatus every shot (pattern A, B, C), in the case of printing aportion of a pattern A, the portions of the patterns B and C are hiddenby the blade, thereby preventing light from transmitting to the patternsB and C. When each of the patterns B and C is printed, processes areexecuted in a manner similar to those mentioned above.

After the patterns A, B, and C are formed, by executing ordinarysemiconductor manufacturing processes such as etching, impuritydiffusion, a CVD (Chemical Vapor Deposition) method, and the like, inaccordance with the patterns, patterns in the second layer are formed.

Subsequently, in the second layer, a second reticle 106 shown in FIG.13C is used and the alignment marks 102 serving as parent marks formedin the first layer are aligned so as to be matched with alignment marks104 serving as child marks. That is, the alignment marks are aligned sothat a pattern A′ lies on the pattern A and a pattern B′ lies on thepattern B. When patterns A′, B′, and C′ are exposed, they are exposed bychanging the position of the masking blade in a manner similar to thefirst layer.

In the prior art, in the case wherein a wiring having an area whichoverlaps the connecting position is formed by using a connectingexposure technique such that the divided patterns are connected andexposed, the wiring which overlaps the connecting position is formed soas to have a margin which takes into consideration the alignmentprecision of the right and left shots with respect to the connectingposition, as shown in FIG. 14. In FIG. 14, A denotes a width of wiringformed by the exposure using the reduction projecting apparatus formicrominiature working; A′ a width of wiring formed by divisionalexposure; and B a width of wiring formed by batch processing of exposureusing the reduction projecting apparatus of a large exposure area. A′ isset to be larger than A in consideration of the margin in the connectingarea. Although a method of changing the connecting position for everylayer, for example, a method of changing the connecting position of thesecond layer to a position which perpendicularly crosses the connectingposition of the first layer is also considered, there is a problem suchthat the apparatus and the processes become complicated.

However, in the semiconductor device and solid state image pickup devicehaving a plurality of wiring layers, in which the wiring layer havingthe area which overlaps the connecting position and the wiring layerwhich does not have the area which overlaps the connecting positionexist, if the patterns obtained by dividing the wiring layer having thearea which overlaps the connecting position are connected and formed,since the patterns are formed in consideration of the alignment marginas mentioned above, there is a case where, in spite of the fact that thenumber of processing steps is increased and the reduction projectingapparatus for microminiature working is used, it is not advantageous interms of the wiring width and a space between the wirings as comparedwith those in the case of forming the patterns by the batch processingof exposure by using the reduction projecting apparatus of the largeexposure area.

SUMMARY OF THE INVENTION

The invention is made in consideration of the above problems and, in amanufacturing method of a semiconductor device using connectingexposure, it is an object of the invention to provide a method ofefficiently manufacturing a semiconductor device in which the number ofprocessing steps is reduced and high sensitivity is obtained.

To accomplish the above object, according to the invention, there isprovided a method of manufacturing a semiconductor device having aplurality of wiring layers, wherein a first wiring layer is formed as apattern by dividing a desired pattern into a plurality of patterns,connecting the divided patterns, and exposing them, the first wiringlayer being formed in parallel with a connecting position, and a secondwiring layer which intersects the connecting position of the firstwiring layer is formed as a pattern by batch exposure processing.

In a manufacturing method of manufacturing a solid state image pickupdevice using connecting exposure, it is another object of the inventionto provide a method of efficiently manufacturing a solid state imagepickup device in which the number of processing steps is reduced andhigh sensitivity is obtained.

To accomplish the above object, according to the invention, there isprovided a manufacturing method of manufacturing a solid state imagepickup device including pixels each having a photoelectric convertingarea for converting light into signal charges and a plurality of wiringlayers comprising a first wiring layer and a second wiring layer,wherein the first wiring layer is formed as a pattern by dividing adesired pattern into a plurality of patterns, connecting the dividedpatterns, and exposing them, and the second wiring layer is formed as apattern by batch exposure processing.

Other features and advantages of the present invention will be apparentfrom the following description taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a unit pixel of a first embodiment of a solidstate image pickup device formed by using a manufacturing method ofmanufacturing a solid state image pickup device of the invention;

FIG. 2 is a plan view for explaining connecting exposure in the firstembodiment;

FIG. 3 is a plan view for explaining connecting exposure in the firstembodiment;

FIGS. 4A and 4B are diagrams for explaining a method of manufacturing asemiconductor device of the invention;

FIGS. 5A and 5B are diagrams for explaining a method of manufacturing asemiconductor device of the invention;

FIG. 6 is an equivalent circuit diagram of a unit pixel of a CMOS sensorin the first embodiment1;

FIG. 7 is an equivalent circuit diagram for explaining the operation ofthe CMOS sensor in the first embodiment1;

FIG. 8 is a timing chart for explaining the operation of the CMOS sensorin the first embodiment;

FIG. 9 is a plan view of a unit pixel of a second embodiment of a solidstate image pickup device formed by using the method of manufacturingthe solid state image pickup device of the invention;

FIGS. 10A and 10B are schematic cross-sectional views taken along theline 10—10 in FIG. 1;

FIGS. 11A and 11B are schematic cross-sectional views taken along theline 11—11 in FIG. 9;

FIG. 12 is an equivalent circuit diagram of the solid state image pickupdevice formed by using the method of manufacturing the solid state imagepickup device of the invention;

FIGS. 13A, 13B, and 13C are schematic pattern diagrams for explaining amethod of manufacturing a semiconductor device in the prior art; and

FIG. 14 is a diagram for explaining a shape of a wiring at a connectingposition in the case of using connecting exposure in the prior art.

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention and,together with the description, serve to explain the principles of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1

FIG. 1 is a plan view of a semiconductor device formed by using a methodof manufacturing the semiconductor device of the invention. In theembodiment, a solid state image pickup device having photoelectricconverting areas for converting light into signal charges will beexplained as an example of the semiconductor device. However, theinvention is not limited to the solid state image pickup device, but itis sufficient to use a semiconductor device having a plurality of wiringlayers.

In FIG. 1, reference numeral 1 denotes a photodiode serving as aphotoelectric converting area; 2, a source follower input MOS transistorserving as an amplifying transistor; 3, a transfer MOS transistorserving as a transfer switch; 4, a reset MOS transistor serving as areset switch; 5, a select MOS transistor serving as a selecting switch;6, a vertical signal line (vertical direction wiring) formed by a firstwiring layer; and 11, a unit pixel area. As a unit pixel area 11 in theembodiment, the unit pixel area formed by a process of a ComplementaryMetal Oxide Semiconductor (CMOS) including the photodiode 1, sourcefollower input MOS transistor 2, transfer MOS transistor 3, and selectMOS transistor 5 is used as an example. However, the invention is notlimited to such a pixel structure, but can be applied to an IC chipincluding a logic circuit, a CCD type image pickup device, or the like,so long as a plurality of wiring layers are used. Reference numeral 12denotes a drive wiring (horizontal direction wiring) formed by a secondwiring layer; 13, a GND wiring (horizontal direction wiring) formed bythe second wiring layer; 14, a source-drain region of the transistor;and X—X, a connecting position at the time when a plurality of patternsare connected by using a connecting exposure technique. The connectingposition is set in the case of forming the vertical signal line, or thelike, formed by the first wiring layer and arranged in parallel with avertical output line.

Each of the first wiring layer and the second wiring layer can bereplaced with a plurality of wiring layers.

For example, although the drive wiring 12 and the GND wiring 13 areformed as a first wiring layer by the same wiring layer in theembodiment, they can be formed by different wiring layers. A combinationof the wirings is not limited to it either.

In the diagram, a connection of a GND and the GND wiring and aconnection of a gate and the drive wiring are omitted.

Although only two pixels are shown in FIG. 1, in an actual solid stateimage pickup device, a number of pixels with such a structure areadjacently arranged in a two-dimensional shape.

The embodiment is characterized in that the vertical signal line 6,which does not have an area which overlaps the connecting position, isformed by, for example, the connecting exposure by the reductionprojecting apparatus for microminiature working and the drive wiring 12and the GND wiring 13 each having the area which overlaps the connectingposition are formed by batch exposure processing.

That is, it is characterized in that the second wiring layer having thearea which overlaps the connecting position is formed as a pattern bythe batch exposure processing.

In the first wiring layer to form the wiring, which does not have thearea which overlaps the connecting position, microminiature wirings canbe formed by a reduction projecting apparatus for microminiatureworking. That is, the pattern is obtained by dividing a desired patterninto a plurality of patterns, connecting the divided patterns, andexposing them.

Therefore, according to the wiring layer to form the wiring having thearea which overlaps the connecting position, as compared with the caseof forming the wiring layer by the connecting exposure, the number ofprocessing steps can be remarkably reduced and a solid state imagepickup device of high sensitivity can be efficiently obtained.

For example, assuming that the solid state image pickup device as asemiconductor device has a plurality of pixels, as shown in FIG. 1, andhas a rectangular shape in which a major side is set in the lateraldirection and a minor side is set in the vertical direction, since anaspect ratio of the valid area in the shot in the pattern created by thereduction projecting apparatus is equal to almost (vertical:lateral=1:1), it is desirable to use a method of dividing a chip intotwo patterns in the horizontal direction, as shown in FIG. 2, or amethod of dividing the chip into three patterns in the horizontaldirection, as shown in FIG. 3, in order to realize the efficientconnecting exposure.

FIG. 2 shows the case where a chip 200 is divided into two patterns of apattern L and a pattern R at a connecting position 201, the pattern L isexposed by a shot L, and the pattern R is exposed by a shot R,respectively.

FIG. 3 shows the case where a chip 300 is divided into three patterns ofthe pattern L, a pattern M, and the pattern R at connecting positions301 and 302, the pattern L is exposed by the shot L, the pattern M isexposed by a shot M, and the pattern R is exposed by the shot R,respectively.

FIG. 4A is a diagram for explaining a state where a first layer (metal1) including the vertical direction wiring, which does not have the areawhich overlaps the connecting position of the patterns L and R, isformed as a pattern by the connecting exposure. One chip is divided intotwo patterns by a dividing position in the diagram and the dividedpatterns are connecting-exposed by the shots L and R, thereby forming adesired pattern. In the unit pixel of FIG. 1, as a connecting position401, a position which does not overlap the first layer (metal 1) isselected. FIG. 4B is a diagram for explaining a state where the secondlayer (metal 2) is formed as a pattern by the batch exposure processing.The reason why the batch exposure processing is used is because if thesecond layer is divisionally exposed and pattern-formed at theconnecting position used in the first layer, the wiring has an areawhich overlaps the connecting position.

According to the manufacturing method of the embodiment as describedabove, by assuring a high numerical aperture, the sensitivity can beimproved or by obtaining a proper opening shape, the sensitivity of theperipheral pixels can be improved.

In the shot of the reduction projecting apparatus, the more height animage has, the more the resolution deteriorates. For example, when theheight of an image increases, the resolution of a portion near theconnecting position 401 in FIG. 4A deteriorates. That is, when a patternexists near the connecting position 401, a defective pattern can becaused due to the deterioration of the resolution. To avoid such adefective pattern, as shown in FIG. 5B, a method whereby one chip isdivided into three patterns by connecting positions 501 and 502 and thedivided patterns are connecting-exposed by the shots L, M, and R,thereby forming a desired pattern, is considered. Thus, thesemiconductor device or the solid state image pickup device can beformed by forming a better pattern in a portion of a low image, that is,a portion near the center of a lens of high resolution.

The positions of the connecting positions and the number of connectingtimes can be properly determined in accordance with a size of a chip orperformance of the exposing apparatus and are not limited to those shownin the embodiment.

Subsequently, FIG. 6 is a circuit diagram showing an example of a unitpixel of a CMOS sensor which can be installed in a solid state imagepickup device formed by the method of manufacturing the semiconductordevice and the solid state image pickup device of the invention.

Portions similar to those mentioned above are designated by the samereference numerals.

Specifically speaking, the photodiode 1 is connected to a gate of thesource follower input MOS transistor 2 via the transfer MOS transistor3. A source of the source follower input MOS transistor is connected tothe vertical signal line 6 via the select MOS transistor 5. The resetMOS transistor 4 to reset the gate of the source follower input MOStransistor 2 to a predetermined electric potential is provided. The GNDwiring connected to the GND is provided for every pixel to suppress atransient fluctuation of a GND potential upon driving (not shown) inFIG. 6.

Subsequently, the operation of the pixel will be explained withreference to an equivalent circuit diagram of FIG. 7 and a timing chartof FIG. 8. In FIG. 7, a unit pixel is shown by the equivalent circuitdiagram of FIG. 6. In FIG. 7, a connection of the unit pixel and the GNDis omitted. When a certain row (assumed to be the nth row) is selectedby a vertical scanning circuit 7, first, a reset signal fRES(n) is setto the low level and the reset switch is turned off. Subsequently, aselection signal fSEL(n) is set to the high level and the selectingswitch is turned on. Thus, the source of the amplifying MOS transistoris made conductive with the vertical output line. A source followercircuit is formed by the selected pixel and a constant current source 8.Subsequently, a signal fTN is set to the high level and an N outputcorresponding to the reset state of the pixel is read out to a linememory 9 via a transfer gate. After that, the transfer switch is held inan ON state for a predetermined period of time by a transfer pulsefTX(n). A photosignal generated in the photoelectric converting elementis transferred to the gate of the amplifying MOS transistor.Subsequently, a signal fTS is set to the high level and an S outputcorresponding to the photosignal is read out to the line memory.Subsequently, an N signal and an S signal of a column selected by ahorizontal scanning circuit 10 are successively read out. By calculatinga difference between the N signal and the S signal having a correlation,a photo response output can be obtained.

After the signals of the pixels of the selected row are simultaneouslytransferred to the line memory, they are successively read out asmentioned above. Therefore, control lines of the select MOS transistorto drive the pixel, the transfer MOS transistor, and the reset MOStransistor are constructed by horizontal direction wirings which overlapthe connecting positions and signal lines which do not overlap theconnecting positions are constructed by vertical direction wirings. Inthe embodiment, the GND wiring is formed in the horizontal direction soas to have the area which overlaps the connecting positions.

Embodiment 2

FIG. 9 is a plan view of a semiconductor device formed by using themanufacturing method of the semiconductor device of the invention. Inthe second embodiment, a solid state image pickup device having aphotoelectric converting area for converting light into signal chargeswill be described as an example of the semiconductor device in a mannersimilar to the first embodiment. However, the invention is not limitedto the solid state image pickup device, but it is sufficient to use asemiconductor device having a plurality of wiring layers.

Reference numeral 20 denotes a GND wiring which is formed by the firstwiring layer.

Portions similar to those mentioned above are designated by the samereference numerals.

In a unit pixel shown in FIG. 9, in order to assure a high numericalaperture, the drive wiring 12 having the area which overlaps theconnecting position is formed by the second wiring layer and the GNDwiring 20 and vertical output line 6, which do not have the area whichoverlaps the connecting position, are formed as vertical directionwirings by the first wiring layer. In the embodiment, the horizontaldirection wiring serving as a second wiring layer is constructed by(metal 2) and the first wiring layer is constructed by (metal 1).

The embodiment relates to an example of a layout diagram in the casewherein the GND wiring of the unit pixel shown in FIG. 6 is constructedby the vertical direction wiring. In the diagram, a connection betweenthe gate and the drive wiring is omitted. That is, the number of wiringswhich are formed by the divisional exposure is set to be larger than thenumber of wirings which are formed by the batch processing of exposure.

Although only two pixels are shown in FIG. 9, in an actual solid stateimage pickup device, a number of pixels of such a structure areadjacently arranged in a two-dimensional shape.

The second embodiment differs from the first embodiment with respect tothe following point. That is, in the first embodiment, the GND wiring 13is arranged by the batch processing of exposure so as to have the areawhich overlaps the connecting position. In the second embodiment,however, the GND wiring 20 is formed by using the connecting exposuretechnique so as not to have the area which overlaps the connectingposition.

Specifically speaking, as mentioned above, in the case of the wiringlayer to form the wiring having the area which overlaps the connectingposition, even if the connecting exposure technique is used, since it isnecessary to consider the margin, there is a case wherein it is notadvantageous in terms of the wiring width and a space between thewirings as compared with those in the case of performing the batchprocessing of exposure. In other words, in the case of the second wiringlayer to form the wiring having the area which overlaps the connectingposition, even if either the method by the batch processing of exposureor the method by the connecting exposure is used, the microminiatureworking cannot be executed with respect to the wiring width and thespace between the wirings. There are, consequently, caused a decrease innumerical aperture, deterioration of the sensitivity, deviation of theshape of the opening, and deterioration of the sensitivity of theperipheral pixels. Therefore, it is preferable to reduce the number ofwirings which are formed by the second wiring layer having the areawhich overlaps the connecting position as much as possible.

Further specifically explaining, FIGS. 10A, 10B, 11A, and 11B arediagrams schematically showing cross-sectional views taken along theline 10—10 in FIG. 1 and the line 11—11 in FIG. 9, respectively, andeach showing a state of an incident light beam. FIG. 10A shows a centerpixel arranged near the center of the solid state image pickup device inthe case wherein the solid state image pickup device shown in FIG. 1 inthe first embodiment has, for example, three million pixels. FIG. 10Bshows a peripheral pixel arranged near the edge portion of the solidstate image pickup device shown in FIG. 1 in the embodiment in the casewherein the device has, for example, three million pixels. FIG. 11Ashows a center pixel arranged near the center of the solid state imagepickup device shown in FIG. 9 in the embodiment in the case wherein thesolid state image pickup device has, for example, three million pixels.FIG. 11B shows a peripheral pixel arranged near the edge portion of thesolid state image pickup device in the case wherein the solid stateimage pickup device shown in the FIG. 9 embodiment has, for example,three million pixels.

In FIGS. 10A and 10B, (metal 2) is the wiring layer having the drivewirings 12 and GND wiring layers 13 of the select MOS transistor 5,transfer MOS transistor 3, and reset MOS transistor 4. Metal 3 functionsas a light shielding layer also serving as a power wiring line. In thecenter pixel shown in FIG. 10A, an optical path is determined by the GNDwiring layer 13 formed by (metal 2) and the drive wiring 12 of thetransfer MOS transistor 3. However, as shown in FIG. 10B, in theperipheral pixel, since an area of the light entering from the obliquedirection is larger than that of the center pixel, an amount of opticalpath which is shielded is larger than that of the center pixel (FIG.10A), so that the sensitivity of the peripheral pixel is lower than thatof the center pixel in many cases.

In FIGS. 11A and 11B, since the GND wiring 13 is formed by another metallayer, an opening portion of an optical path is specified by the drivewirings of the transfer MOS transistor 3 and the select MOS transistor5. Therefore, even if the light enters the peripheral pixel (FIG. 11B)from the oblique direction, since the opening portion is wide, theoptical path is hardly shielded. Thus, a solid state image pickup devicein which the variation in sensitivity of the center pixel and theperipheral pixel is further reduced can be provided.

In the first and second embodiments, the second wiring layer can beconstructed by (metal 1) and the first wiring layer can be constructedby (metal 2). In this case, by pattern-forming (metal 2) by theconnecting exposure and pattern-forming (metal 1) by the batchprocessing of exposure, the effects of the embodiments are obtained.

In the invention, the equivalent circuit diagram of the unit pixel isnot limited to the example shown in FIG. 6, but can be applied to asemiconductor device and a solid state image pickup device in which apattern is formed by using both of the connecting exposure and the batchprocessing of exposure. For example, similar effects are obtained evenin a solid state image pickup device in which a plurality of unit pixelseach shown in the equivalent circuit diagram of FIG. 12 are arranged ina matrix form. FIG. 12 differs from FIG. 6 with respect to the followingpoint. That is, in FIG. 6, the select MOS transistor 5 is connected tothe vertical output line 6 on the side opposite to the source followerinput MOS transistor 2. In FIG. 12, the select MOS transistor 5 isconnected to the power source on the side opposite to the sourcefollower input MOS transistor 2. Operation timings are similar in bothcases.

Moreover, an arrangement is preferred in which the number of wirings,which do not have the area which overlaps the connecting position, isset to be larger than the number of wirings which are formed by thewiring layers which overlap the connecting position.

1. A manufacturing method of manufacturing a semiconductor device havinga plurality of wiring layers, said method comprising the steps of:forming a first wiring layer divided into a plurality of patterns, andexposing them, wherein a position of a connection of the dividedpatterns is formed in parallel with the wiring which is formed by thefirst wiring layer; and forming a second wiring layer having an areawhich intersects the connecting position by batch processing ofexposure.
 2. A method according to claim 1, wherein the wiring which isformed by the first wiring layer does not have an area which overlapsthe connecting position and the wiring which is formed by the secondwiring layer has the area which overlaps the connecting position.
 3. Amethod according to claim 1, wherein the first wiring layer is ahorizontal direction wiring layer which is parallel with the connectingposition for connecting the divided patterns and the second wiring layeris a vertical direction wiring layer which perpendicularly crosses theconnecting position.
 4. A method according to claim 1, wherein alignmentof the pattern for forming the first wiring layer and the pattern forforming the second wiring layer is made by a die-by-die system.
 5. Amanufacturing method of manufacturing a solid state image pickup devicehaving pixels each having a photoelectric converting area for convertinglight into signal charges and a plurality of wiring layers including afirst wiring layer and a second wiring layer, said method comprising thesteps of: forming a first wiring layer divided into a plurality ofpatterns, and exposing them, wherein a position of a connection of thedivided patterns is arranged in parallel with the wiring which is formedby the first wiring layer; and forming a second wiring layer having anarea which intersects the connecting position by batch processing ofexposure.
 6. A method according to claim 5, wherein the wiring which isformed by the first wiring layer does not have an area which overlapsthe connecting position for connecting the divided patterns and thewiring which is formed by the second wiring layer has the area whichoverlaps the connecting position.
 7. A method according to claim 5,wherein a vertical direction wiring is formed by the first wiring layer,and a horizontal direction wiring is formed by the second wiring layer.8. A method according to claim 7, wherein the horizontal directionwiring is a drive wiring of the pixels.
 9. A method according to claim5, wherein before the step of forming the plurality of wiring layers, aCMOS process is included at the time of the pixel creation.
 10. A methodaccording to claim 5, wherein alignment of the pattern for forming thefirst wiring layer and the pattern for forming the second wiring layeris made by a die-by-die system.